This invention relates to laboratory equipment for drying flat gel slabs following their use in electrophoretic separations.
Once the bands occurring in electrophoresis through a gel slab have been formed and spread across the slab, the slab is dehydrated or "fixed" for purposes of preservation and analysis of the electrophoretic pattern. Existing devices for doing this use heat, vacuum or both to dehydrate the gel. One example of such a device is that shown in Fernwood et al., U.S. Pat. No. 4,612,710 (issued Sept. 23, 1986). This and other similar devices rely in part on a vacuum applied to the gel slab from beneath.
An important feature of such a device is that the vacuum be evenly distributed over the entire gel slab, and there be no substantial leaks which would introduce irregularities in the vaporization rate in any region of the slab. As explained in the Fernwood et al. patent, uneven drying raises a risk of causing cracks in the gel as it dries, ultimately distorting the shape of the fixed gel. These devices are particularly susceptible to unreliable vacuum seals which can be both difficult to initiate and prone to continuous leakage due to misalignment of the gel stack components in the recess, and debris at the edge of the recess.